This densely constructed and well-written piece of scholarship...truly deserves to be widely read and considered...heralds the coming of a new voice on the scene of public international law, a voice worth considering. Jean Allain Journal of African Law, Vol 50 June 2006 ...Ademola Abass has succeeded in writing an extremely interesting book on a highly relevant and practical subject...it is certainly a merit of the book that it does not merely describe and analyze the current developments but tries to develop innovative approaches which may lead in new directions. Christian Walker German Yearbook of International Law, Vol 48 2005 ...lively and well documented a realistic examination of the evolution of collective security. ASIL Newsletter June 2005 ...an excellent book for those interested in the issue of development of the law and practice of collective security by regional organisations after the Cold War. Emmanouela Mylonaki, University of Bristol African Journal of International and Comparative Law June 2005